|Meredith Jr, William|
Submitted to: National Cotton Council Beltwide Cotton Conference
Publication Type: Abstract Only
Publication Acceptance Date: 3/4/2005
Publication Date: 6/4/2005
Citation: Davidonis, G.H., Meredith Jr, W.R., Heiholt, J., Richard, O.A., Ingber, B.F. Effects of seed weight changes on fibers per seed and fiber property uniformity. National Cotton Council Beltwide Cotton Conference. 2005. p. 1932. Interpretive Summary:
Technical Abstract: The average weight of a fiber is determined by the extent of primary and secondary wall development. Yield can be increased by increasing fiber weight and/or the number of fibers per seed. Since increasing fiber weight in some genotypes has the potential to increase micronaire to unacceptable levels, strategies need to be developed that limit cell wall deposition. Seed weight has shown a positive correlation with micronaire. Since and increase in the number of seeds per boll decreases average seed weight, strategies that alter the number of seeds per boll would be expected to alter fiber properties. Characterization of the relationship between seed weight, fibers per seed and fiber properties will supply basic information for strategy development. Cotton (Stoneville 474 and FiberMax 832)was grown under irrigated conditions in 1998 and 1999. First position bolls were tagged on 7/13-7/15/1998 (node 13-19) and on 8/2-8/4/1999 (nodes 15-19. For each tagged boll, mean seed weight and fiber properties were obtained. Fiber was analyzed using AFIS. The number of fibers per seed was calculated from AFIS length and fineness measurement using the relationship that, Fiber weight per seed=(AFIS mean length)(AFIS millitex)(number of fibers). Maximum seed weight was higher in 1999 than in 1998. In 1998 variability in bolls samples resulted in poor correlations between seed weight, fibers per seed, mean fiber length, mean length variability and cell wall thickness. In 1999, as seed weight increased, the number of fibers per seed increased. FiberMax 832 at maximum seed weight (153 mg)had more fibers than Stoneville 474 at maximum seed weight (129 mg). As seed weight increased, fiber mean length and cell wall thickness increased. Fiber length variability was experessed as mean length coefficient of variation [L(w)CV]. As seed weight increased, length uniformity increased. An increase in length uniformity paralleled the increase in cell wall thickness. At maximum seed weight, Stoneveille 474 had an L(w)CV of 17% while FiberMax 832 had an L(w)CV of 19%. Strategies to increase the number of seeds per boll may reduce micronaire values and decrease length uniformity. These strategies include the reduction in the number of unfertilized ovules per boll.